What is the fourth dimension?

The 4th direction is taken as time. To understand this imagine every space we placed next to one another being associated with a moment of time, like images are associated with time in a video and series of these images when played make up a video.

In Physics we call these 4dimensions as spacetime. One element(space) of 4th dimension is exactly one moment in the universe, and series of this describe the whole timeline of events taking place from very beginning to the future of the universe.

:-)

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west